Obstructive sleep apnoea and its association with gestational hypertension

¹ Dept Medicine, Respiratory Epidemiology and Clinical Research Unit, McGill University
² Dept Medicine, FetoMaternal Unit, McGill University
³ Dept Microbiology, Santa Cabrini Hospital
⁴ Dept Obstetrics, McGill University
⁵ Dept Medicine, McGill University

^* To whom correspondence should be addressed. E-mail: kateri.champagne{at}muhc.mcgill.ca.

	Abstract

Hypertension develops in 10% of pregnancies. Snoring, a marker for obstructive sleep apnoea, is a newly identified risk factor for gestational hypertension. Moreover, obstructive sleep apnoea is an independent risk factor for incident hypertension in the non-pregnant population.

Test the hypothesis that obstructive sleep apnoea is associated with new onset of hypertension among pregnant women.

Case-control study involving 17 pregnant women with gestational hypertension and 33 pregnant women without hypertension, frequency-matched for gestational age, recruited in a tertiary obstetrical centre. Obstructive sleep apnoea was ascertained by polysomnography, and defined by an apnoea-hypopnoea index 15 events per hour, without a requirement for desaturation.

The mean apnoea-hypopnoea index for normotensive pregnant women was 18.2±12.2 (SD) events·h^-1 compared with 38.6±36.7 events·h^-1 for women with hypertensive pregnancies (p=0.005). The crude odds ratio for the presence of obstructive sleep apnoea given the presence of gestational hypertension, was 5.6. The odds ratio was 7.5 (95% CI 3.5–16.2), based on a logistic regression model with adjustment for maternal age, gestational age, pre-pregnancy body mass index, prior pregnancies, and previous live births.

Gestational hypertension appears to be strongly associated with the presence of obstructive sleep apnoea.